Tuesday, October 18, 2005

KST Day 5-6: Go signal

I had several chats with Alex von Gudenberg, and how to structure an evaluation of the therapy. We also exchanged ideas on which elements are crucial and which ones are not. The best method would obviously be to start from a well-establish theory of PDS, which we do not have right now. However, I think that one theory or rather observation is an important one and likely true: stuttering is caused by a failure to initiate the first sound. This is a conceptual statement. A more physical statement (but slightly different issue) is that the region that sends the motor plan to the muscles does not receive a GO signal (to initiate the sound). Why this is so is another story and not directly relevant. If we assume that the stuttering event starts with a failure to initiate the (first) sound, a therapy should reduce the occurence of such failures. Fluency shaping might do it by teaching people a gentle onset. The effect is 1) the gentle onset trains the ability to initiate (as you have to concentrate before speaking) AND 2) allows to start gently which makes it mechanically impossible to block. Van Ripper style therapies might also train the ability to initiate by doing block modification. So possibly both very different approaches work on the failure to initiate, but dont know it! The big question is whether any other exercise would more efficiently train this, possibly only phonation could help. I think this is also what Prof Ingham has been/is trying. He sent me an article some time ago. I have to re-read it again... Sorry this paragraph is a bit messy, it need to get it clearer in my mind.

Regarding the therapy, we have moved into using the speech technique in more realistic settings. Currently, we over-do the technique (gentle onset, connecting syllables), and the patients need to practice also outside the therapy session. However, thatÂ´s very difficult for some. Also for me, I want to apply it all the time, but I often forget... An hour ago, I recorded myself unintentionally, and when I listened to the recording I did not apply the techniques all the time and had dysfluencies. But the strange thing is that I did notrealizee my dysfluencies, only after I listened to the recording. But I am pretty good at getting into the techniques. Some patients have trouble to stay in technique more and show stuttering symptoms. But even for them, if they repeat it again, they become pretty fluent. It is really amazing how fluent even the worst stuttering can become... This still leaves me wondering whether a cure (or much more efficient therapy) is not possible in some way. If they can speak fluent, it must be possible to get this sorted somehow.

Well. In one of my last posts, I said that there might be two pathways: an unstable automatic one, and a stable active-control one. And one of the two can give GO signals to initiate the (first) sound.

DAF or FAF has a fluency-enducing effect like chorus reading, rhythmic speech, imitating a foreign accent, and so on. So it is possible that for DAF or FAF the brain does not identify the speech as its own and goes to the active-control model which works properly and enducing fluency.

The fact that the brain "does not recognize the speech pattern as its own" may implicate a different or additional activation, thus compensating a deficient activity to properly execute the motor plans. This however, does not fit with the "lucky fluencies", since the automatic pathway SEEMS to be the only one active. I suppose we have to differentiate the source of this wondrous change in the symptoms. This, however, may still be far beyond our actual possibilities.